package main

func main()  {

}

type deepTreeNode struct {
	val int
	left *deepTreeNode
	right *deepTreeNode
}
func maxDeep(root *deepTreeNode) int  {
	if root == nil {
		return 1
	}
	leftMax := maxDeep(root.left)
	rightMax := maxDeep(root.right)
	var max int
	if leftMax > rightMax {
		max = leftMax
	}else {
		max = rightMax
	}
	return max + 1
}